Process of utilizing the heat of the generator of superpressure steam generators



Sept. 17, 1929. w. STENDER 1,728,375

PROCESS OF UTILIZING THE HEAT OF THE GENERATOR OF SUPERPRESSURE STEAM GENERATORS Filed Dec. 1. 1926 CLOSED Patented Sept. 17, 1929 UNITED STATES PATENT OFFICE WALDEMAR STENDER, OF BERLIN-CHARLOTTENBURG, GERMANY, ASSIGNOR TO SIEMENS-SCHUCKERTWERKE GESELLSCHAFT MIT ZBESGHRANKTER HAFTUNG, OF

BERLIN-SIEMENSSTADT, GERMANY, A CORPORATION OF PROCESS OF UTILIZING-THE HEAT GERMANY OF THE GENERATOR OF SUPERPBESSURE STEAM GENERATORS Application filed December 1, 1988, Serial No. 151.942, and in Germany December 4, 1925.

My invention relates to a process of utilizing. the heat of thegenerator of super-pressure steam generators.

Super-pressure or maximum pressure steam generators consist substantially of a heated system of pipes and thus possess either a very small Water'space or none at all. i If such a steam generator is stopped a large quantity of heat is stored up in its material which it was impossible heretofore to utilize economically. In order not to endanger the system of pipes by the accumulation of heat after the stoppage of the steam generation, it was hitherto necessary to open an outlet for the steam either into the condenser 01' through the safety valve into the atmosphere so that circulation of the water within the generator could be maintained. In both cases the quantity of heat which has to be discharged from the boiler is a. waste. It is the object of my invention to eliminate this waste and I attain this end in view by continuin to pass water through the generator after tne closing of the live steam supply ipe and the stopping of the furnace, but eading this highly heated water into an accumulator until the generator is' cooled down,

In the accumulator there is thus at the end It) of this procedure stored up a certain quantity of-heat, which mayin an economical manner be utilized for heating up the generator when commencing operations. This is effected in such a way that when taking the 85 generator into service the feed water is first taken from the accumulator only and kept in circulation between the generator and the accumulator untilthe steam has attained the desired state (pressure, temperature). Onl then is the steam service pipe opened. 1 f desired the generator may be fed from the accumulator until the latter is run empty.

The foregoing idea may be still further developed in economical respects in cooperation with a steam regenerative accumulator. If after stoppage of the furnace the water is pumped into the water accumulator a part of the water will turn into steam, since the pressure in the accumulator is preferably 60 kept lower than in the generator. This steam v steam in the accumulator is so great that the power required for the pump 1s covered by it.

In the drawing afiixed hereto my novel idea is embodied in a practical arran ement or system illustrated diagrammatical y.

Referring to this drawing, 1- is a steam generator with a' su erheater 2'which feeds a live steam pipe 3 eading to the steam engine 4 which drives a dynamo 5. The quantity of steam supplied to the engine 4 by 66 the pipe 3 is regulated in well known manher by means of a throttling valve 6 which operates in dependence from the pressure in the pipe 3. The engine 4 operates as a so-called back-pressure engine upon a back 0 pressure pipe 7 with which are connected the engines 9 and 10. The engine 10 comprises the stages 11 and 12. The exhaust of the engines 9 and 10 is condensed in the condensers 13 and 14, the condensate from which is passed into a feed water well 16 by a pipe 15. A pump 17 withdraws the feed water from the well 16 and forces it into a steam preheater 18 and from it partly into an accumulator 19 whose input side is controlled by a valve 32 and partly to a pump 20 according to the requirements of the steam generator 1. Between the pump 20 and the generator is further connected 8 flue gas preheater 21. Between the highpressure and the low-pressure vapour s stern is provided a connecting pipe 22 whlch in-the event of an. excess-of steam in the pipe 3 allows steam to flow into the pipe 7 y a pressure responsive device 23 controlling throttle valve 23. If the steam consumption of the engines 9 and 10 is less than the volume of steam available in the pipe 7, the surplus steam is passed to a steam accumulator 26 by a pipe-24 in which a throttle 5 valve 25, controlled by a pressure responsive device 25 is located. This steam accumulator 26 communicates with the stage 12 of the prime mover 10 by a pipe 27. A control valve 33 controlled by a pressure responsive device 28 opens a path for the accumulator steam to the sta e 12 if the supply from line 7 no longer su ces for covering the power.

requirement of the two engines 9'and 10.

The stopping of the plant according to the present system occurs in the following man ply to main 3 is stopped'by closingthe maln I service valve 29, and that the heat supply 7 (not she "11) to the generator is discontinued. Valve 32 is now closed'and the pumps quite a high temperature due to the heat stored in the boilerand thus removesthe 25 heat from the boiler. The water accumulator 19 is connected with the pipe 3 by a pipe 31 controlled by a valve 37 and rece ves this way the water forced by the pump through the boiler. The valve 32 remains closed dur i ing thestopping process, while valve 37 in pipe 31 is opened. The steam expelled from the water in the accumulator 19 enters the pipe 7 and continues to drive the engine 10. If the quantity of steam issuing from the accumulator 19 is larger than the requirement of the engine 10 the surplus is conveyed to the accumulator 26. by way of valve 25". If the volume of steam issuing from the accumulator 19 does no longer suffice for driving the engine 10, the pressure responsive device 28 opens the valve 33 and allows steam to flow from the accumulator 26 to stage 12 of the engine 10. The accumulator 19 should be so dimensioned that it is able to hold the quantity of water necessary for cooling the generator.

The starting oi the steam generator is effected in the following manner: The valves 29 and 38 remain closed while the valve32 is no vs also opened. The pressure in pipe 7 being probably then quite low, valve d3- opens and stage 12 of the engine 10 consequently receives steam from the steam accumulator 26 and starts. The cold water pump 17 is still assumed to be inoperative. while the pump 20 commences to run and withdraws water from the water accumulator 19, which it circulates between the generator 1 and the accumulator 19 until the water has attained the necessary temperature and required pressure. As soon as the desired condition of the steam has been obtained, the valves 29 and 38 are opened while valve 37 is closed and the normal service commences.

Various modifications and changes may be 17 and 20, still running 'feed water into the generator 1 which water becomes heated to made without departing from the spirit and the scope of the invention, and desire,

therefore, that only such limitations shall be placed thereon as are imposed bytth'e prior art. f

I claim as my invention: I 1. Ina steam power plant in combination with a steam generator consisting substanthe service pipe'ior cutting off the steam from the consumers, of a pipe circuit containing a hot feed water accumulator and being connected in parallel to the output side of the generator and 'tlic'iuput sidebf said feed water supply, and valves suitably disposed in said circuit for permitting'a fresh feed water supply through the genera tor'into said accumulator when .fthefioperatron of the generator is dIscontmued to transfer the heat stored in the generator 9 pipes into said accumulator,

. 2. I" a steam power plant in combination with a steam generator consisting substan- A tially of a heated pipe system, a service steam pipe and consumers connectedto the output side water supply means connected to the input side of the generator, and. a main valve in theservice' pipe for cutting off the steam from the consumers, of a pipe circuit containing a hot feed water accumulator, and being connected in parallel to the output side of the generator and the input side of of said generator, and a feed said feed water supply, and a valve disposed at each end of said hot water accumulatorfor permitting the feed water supply means to deliver fresh feedwater througi the generator into said accumulator when the consumers steam supply has been cut off, and when the operation of the generator is discontinued to transfer the heat-' stored in the generator pipes into the feed water delivered into said accumulator, and to permit circulation of heated feed water between the accumulator and saidgenerator by said supply means when the gcnera-= tor operation is resumed and before the con-v sumers steam supply is restored, and means tpr cutting oft the fresh feed water during said circulation period.

3. In a steam power plant in combination with a steam generator consisting. substans t-iallyof a heated pipe system, a service steam pipe connected with the output-iside of said generator for feeding' steam .to consumers including a back pressure engine, anda main valve in the service pipe for cutting off the steam from the consumers, a secondary steam supply systemconnected with the exhaust side of said engine, a prime mover. supplied by said secondary system ias and a steam regenerative accumulator connected with said secondary system to receive the surplus steam not consumed in said secondary system, and a feed water pump connected to the input side of said steam generator and being operated by said prime mover, of a pipe circuit, containing a hot feed water accumulator and being connected in parallel to the generator output side and the feed water pump intake side, valves suitably disposed in said circuit for permitting the feed water pump to deliver fresh feed water through the generator into said accumulator when the consumers steam supply has been cut off and when the operation of the generator is discontinued, to transfer the heat stored in the generator pipes into the feed water delivered into said accumulator, and a pipe connection between the upper,

water accumulator and the steam stored in said steam accumulator.

4. In a steam power plant in combinatlon with a steam generator consisting substantially of a heated pipe system, a service steam pipe connected with the output side of said generator for feeding steam to consumers including a back pressure engine, and a main valve in the service pipe for cutting off the steam from the consumers, a secondary steam supply system connected with the exhaust side of said engine, a prime mover supplied by said secondary system and a steam regenerative accumulator connected with said secondary system to receive the surplus steam not consumed in said secondary system, and a feed water pump connected to the input side of said steam generator and being operated by said prime mover, of a pipe circuit, containing a hot feed water accumulator and being connected in parallel to the generator output side and the feed water pump intake side, valves suitably disposed in said circuit for permitting the feed water pump to deliver fresh feed water throu h the generator into said accumulator w en the consumers steam supply has been cut off and when the operation of the generator is discontinued, to transfer the heat stored in the generator pipes into the feed water delivered into said accumulator, said valves also permitting circulation of hot feed water between the water accumulator and said generator by said supply pump when the generator operation is resumed, means for cutting off the fresh feed water supply during said circulation period, and

,a pipe connection between the upper portion of said water accumulator and said secondary steam supply system to deliver any steam developed during the heat storage in said water accumulator into said secondary system, said prime mover being operated during said heat transfer from the generator jointly by the steam developed in said water accumulator and the steam stored in said steam accumulator, and suitable pipe connection between said steam accumulator and said prime mover and control means in said connection for permitting the operation of said prime mover fromsaid steam accumulator during said resumption period of the generator operation and during said hot water circulation period.

In testimony whereof I aflix my signature.

WALDEMAR- STENDER 

